Rate Of Desaturation Research Articles

Contributions to forearm desaturation during transient ischemia in healthy adult males and females across the lifespan.

This study investigated skeletal muscle tissue oxygenation (StO2) desaturation in males and females across the adult lifespan. One-hundred-two individuals (51 females) of 41 young, 34 midlife, and 27 older adults completed a vascular occlusion test with near-infrared spectroscopy (NIRS+VOT). This included five minutes of arterial occlusion, inducing transient ischemia in the forearm flexor muscle group while recording StO2. The magnitude of desaturation (StO2mag) was quantified as the difference between baseline StO2 and the minimum StO2 value observed during ischemia. The rate of desaturation was also examined. Forearm adipose tissue thickness (ATT), forearm lean mass, and handgrip muscular strength were measured. A p ≤ 0.05 was considered significant. Two-way between factor ANOVAs indicated that males exhibited significantly (p<0.001) less ATT than females (collapsed across age) and that forearm lean mass (p<0.001) and muscular strength (p<0.001) decreased across the lifespan independent of sex. Bivariate analyses revealed significant (p<0.05) associations for sex, age, ATT, forearm lean mass, and muscular strength with the desaturation metrics. The ATT values demonstrated the strongest relations with StO2mag and desaturation rate (r = -0.620 and 0.618). Using a model comparison approach, ATT plus age offered the best predictive power for StO2mag and desaturation rate (R2 = 0.456 and 0.438) such that the inclusion of sex did not improve the models. These findings suggested differences in desaturation were primarily explained by variations in ATT and, to a lesser extent, age, but biological sex had no meaningful effect. Future studies must determine what other factors influence desaturation during ischemia.

Comparison of supraglottic airway device and endotracheal tube in former preterm infants receiving general anesthesia: a randomized controlled trial

To date, endotracheal tube (ETT) remains the mainstream for preterm infants receiving general anesthesia. We aim to compare the perioperative respiratory adverse events between using supraglottic airway device (SAD) and ETT in former preterm infants receiving general anesthesia. Former preterm infants below 52 weeks of postmenstrual age scheduled for herniorrhaphy were randomized to receive SAD or ETT for general anesthesia. Infants with severe congenital cardiopulmonary disease, prolonged oxygen or mechanical ventilation dependence, and recent respiratory tract infection were excluded. Muscle relaxant agents and opioids were avoided in this study. 40 infants were assigned into SAD or ETT groups. Infants in the SAD group had a much lower rate of intraoperative desaturation than those in the ETT group (21.1% vs. 73.7%, p = 0.003). Incidences of other intraoperative and postoperative 24-h respiratory adverse events were similar between groups, including laryngospasm/bronchospasm, cough and stridor during anesthesia, and postoperative apnea, bradycardia, and supplemental oxygen use. All participants were extubated successfully in the operation room. SAD is recommended in former preterm infants receiving general anesthesia for herniorrhaphy in their early infancy as it much decreases the incidence of intraoperative desaturation compared to ETT.

Influence of Long-Term Soccer Training on the Fatty Acid Profile of the Platelet Membrane and Intra-Platelet Antioxidant Vitamins.

This research aimed to study the long-term effects of soccer training on platelet membrane fatty acid levels and antioxidant vitamins. Forty-four subjects divided into soccer players (SP; n = 22; 20.86 ± 0.36 years) and a control group (CG; n = 22; 21.23 ± 0.49 years) participated in the study. The fatty acids of the platelet membrane, the rates of desaturation, lipid peroxidation indexes and intra-platelet levels of vitamins C and E were assessed. SP obtained lower values in polyunsaturated fatty acids 18:3:3 (alpha-linolenic acid), 20:5:3 (eicosapentaenoic acid) and 22:6:3 (docosahexaenoic acid) (p < 0.05). The desaturation index ∆5 was higher in SP (p < 0.05), and they had a higher lipid peroxidation index 20:4:6 (arachidonic acid)/16:0 (palmitic acid) (p < 0.05). Vitamin E and C platelet values were also higher in SP (p < 0.01). There were positive correlations in the ω6/ω3 index (p < 0.05), desaturation index ∆5 (p < 0.05), lipid peroxidation index 20:4:6/16:0 and intra-platelet vitamins E and C (p < 0.01) with the level of physical activity. In addition, there were inverse correlations in fatty acids 24:0 (lignoceric acid), 16:1 (palmitoleic acid), 20:3:6 (eicosadienoic acid) and 18:3:3 (alpha-linolenic acid) (p < 0.05) depending on the degree of physical activity. Regular long-term soccer training could modify the concentration of fatty acids such as 24:0, 16:1, 18:6, 20:3:6, 18:3:3:3, 20:5:3, 26:6:3 and ω3 PUFAs in the platelet membrane.

Comparison of opioid-free and opioid-inclusive propofol anaesthesia for thyroid and parathyroid surgery: arandomised controlled trial.

Postoperative nausea and vomiting occur frequently following thyroid and parathyroid surgery and are associated with worse patient outcomes. We hypothesised that opioid-free propofol anaesthesia would reduce the incidence of postoperative nausea and vomiting compared with opioid-inclusive propofol anaesthesia in patients undergoing these procedures. We conducted a randomised, double-blinded controlled trial in adult patients scheduled to undergo thyroid and parathyroid surgery at two medical centres in mainland China. Patients were allocated randomly (1:1, stratified by sex and trial site) to an opioid-free anaesthesia group (esketamine, lidocaine, dexmedetomidine and propofol) or an opioid-inclusive group (sufentanil and propofol). Propofol infusions were titrated to bispectral index 45-55. Patients received prophylaxis for nausea and vomiting using dexamethasone and ondansetron and multimodal analgesia with paracetamol and flurbiprofen axetil. The primary outcome was the incidence of postoperative nausea and vomiting in the first 48 h after surgery. We assessed 557 patients for eligibility and 394 completed this trial. The incidence of postoperative nausea and vomiting in the first postoperative 48 h was lower in the opioid-free anaesthesia group (10/197, 5%) compared with opioid-inclusive group (47/197, 24%) (OR (95%CI) 0.17 (0.08-0.35), p < 0.001), yielding a number needed to treat of 5.3. Additionally, opioid-free propofol anaesthesia was associated with a reduced need for rescue anti-emetics, lower rates of hypotension and desaturation after tracheal extubation, and higher patient satisfaction. Time to tracheal extubation was prolonged slightly in the opioid-free group. The two groups had similar postoperative pain scores and 30-day outcomes. Opioid-free propofol anaesthesia reduced postoperative nausea and vomiting in patients undergoing thyroid and parathyroid surgery. An opioid-free anaesthetic regimen can optimise anaesthetic care during thyroid and parathyroid surgery.

High-flow nasal oxygen versus conventional oxygen therapy during cesarean section under neuraxial anesthesia in pregnant women with heart disease: a randomized controlled trial

To evaluate the beneficial effects of high-flow nasal cannula (HFNC) oxygen therapy during cesarean section in pregnant women with heart disease. We conducted a single-center, single-blinded randomized trial of HFNC oxygen therapy in pregnant women with heart disease undergoing cesarean section under neuraxial anesthesia.The participants were randomly assigned to receive either HFNC oxygen therapy with inspiratory flow of 30 L/min with 40% FIO2(n=27) or conventional oxygen therapy (COT) with oxygen flow rate of 5 L/min via a nasal cannula (n=31).The primary outcome was maternal desaturation (SpO2 < 94% lasting more than 3 min or PaO2/FIO2≤300 mmHg). Maternal desaturation was observed in 7.4%(2/27) of the women in HFNC group and in 32.3%(10/31) in the COT group.None of the cases required tracheal intubation during the perioperative period.The HFNC group had a significantly higher incidence of postoperative leukocytosis (P < 0.05) but without pyrexia or other inflammation-related symptoms.There were no significant differences between the two groups in the secondary maternal outcomes (need for respiratory support, maternal ICU admission, postoperative respiratory complications, and cardiovascular complications) or neonatal outcomes (P>0.05). In pregnant women with heart disease, HFNC therapy can significantly reduce the rate of maternal desaturation during the perioperative period of cesarean section without adverse effects on short-term maternal or fetal outcomes.

Structural, soil-water, and dynamic characteristics of clay with different moisture and temperature histories

Variations in the hydro-mechanical properties of pavement subgrade soils are complex under long-term, repeated, and interlaced moisture and temperature (M-T) effects, such as wetting-drying (WD) and freeze-thaw (FT) processes. This study compares the soil structure, soil-water characteristic curves, and accumulated plastic strain (ɛ p) of compacted Heilongjiang clay with three different M-T histories. Experimental results demonstrated that (i) after M-T actions, structural pores develop while textural pores shrink, leading to a reduction in the water retention capacity and an increase in the desaturation rate. Following the stabilization of the M-T effects, the soil structure and soil-water characteristics of specimens with different M-T histories become similar; (ii) at high moisture content (w), ɛ p is more sensitive to moisture changes (including w and suction, s). Following the FT cycles, ε p and ε pa (the difference between the ε p at 5000th and 3000th cyclic loading) become more sensitive to moisture changes; (iii) after M-T effects, the ε pa-w relationship is nonlinear while the ε pa-logs relationship is linear. Different M-T histories generated differences in only the ε p at the beginning of the FT processes while such differences disappear after M-T effects have stabilized. The experimental data presented in this paper could prove valuable in understanding the behaviors of pavement soils under complex environmental conditions.

Effectiveness of trans-nasal humidified rapid insufflation ventilatory exchange compared with standard facemask oxygenation for pre- and apneic oxygenation during anesthesia induction: A meta-analysis based on randomized controlled trials.

To further identify the effectiveness of trans-nasal humidified rapid insufflation ventilatory exchange (THRIVE) for pre- and apneic oxygenation during the anesthesia induction by comparison to facemask ventilation (FMV) based on current available evidence. Medline, EMBASE, Web of Science, Cochrane Library and CNKI databases were searched from inception to December 22, 2023 for available randomized controlled trials (RCTs). Primary outcomes were PaO2 and PaCO2 after intubation and safe apnoea time. Secondary outcomes included the O2 desaturation, end expiratory carbon dioxide (EtCO2) and complications. The effect measures for continuous and categorical outcomes were separately the mean difference (MD) and relative risk (RR) with 95% confidence interval. Twelve RCTs with 403 patients in the THRIVE group and 401 patients in th FMV group were included. Pooled results demonstrated that the PaO2 after intubation was significantly higher (MD = 82.90mmHg, 95% CI: 12.25~153.54mmHg, P = 0.02) and safe apnoea time (MD = 103.81s, 95% CI: 42.07~165.56s, P = 0.001) was longer in the THRIVE group. Besides, the incidence rate of O2 desaturation (RR = 0.28, 95% CI: 0.12-0.66, P = 0.004) and gastric insufflation (RR = 0.26, 95% CI: 0.13-0.49, P<0.001) was significantly lower in the THRIVE group. Based on current evidence, THRIVE manifested better effectiveness representing as improved oxygenation, prolonged safe apnoea time and decreased risk of complications compared to standard FMV in surgical patients. Therefore, THRIVE could be served as a novel and valuable oxygenation technology for patients during anesthesia induction.

Noninvasive estimation of skeletal muscle oxygen consumption rate and microvascular reactivity in chronic stroke survivors using near-infrared spectroscopy.

Understanding post-stroke changes in skeletal muscle oxidative metabolism and microvascular reactivity could help create therapeutic targets that optimize rehabilitative interventions. Due to disuse atrophy, we hypothesized that basal muscle oxygen consumption rate and microvascular endothelial function would be impaired in the tibialis anterior (TA) muscle of the affected leg of chronic stroke survivors compared with the nonaffected leg and versus matched controls. Fifteen chronic stroke survivors (10 females) and 15 matched controls (9 females) completed this study. A near-infrared spectroscopy oximeter measured tissue oxygen saturation (StO2) of the TA in both legs of stroke survivors and the dominant leg of controls. A cuff was placed around the thigh and inflated to 225 mmHg for 5 min while StO2 was continuously measured. The rate of change in StO2 was calculated during cuff occlusion and immediately post-cuff release. The rate of oxygen desaturation was similar between the legs of the stroke survivors (paretic -0.12 ± 0.04%·s-1 vs. nonparetic -0.16 ± 011%·s-1; P = 0.49), but the paretic leg had a reduced desaturation rate versus controls (-0.25 ± 0.18%·s-1; P = 0.007 vs. paretic leg). After cuff release, there was a greater oxygen resaturation rate in the nonparetic leg compared with the paretic leg (3.13 ± 2.08%·s-1 vs. 1.60 ± 1.11%·s-1, respectively; P = 0.01). The control leg had a similar resaturation rate versus the nonparetic leg (control = 3.41 ± 1.79%·s-1; P = 0.69) but was greater than the paretic leg (P = 0.003). The TA in the paretic leg had an impaired muscle oxygen consumption rate and reduced microvascular endothelial function compared with controls.NEW & NOTEWORTHY Secondary consequences of stroke are not well described. In this study, we show that basal muscle oxidative consumption and microvascular endothelial function are reduced in the paretic tibialis anterior muscle of chronic stroke survivors compared with matched controls using near-infrared spectroscopy and the vascular occlusion technique. There was a moderately strong correlation between microvascular endothelial function and paretic leg strength.

Age and sex differences in microvascular responses during reactive hyperaemia.

Microvascular impairments are typical of several cardiovascular diseases. Near-infrared spectroscopy (NIRS) combined with a vascular occlusion test provides non-invasive insights into microvascular responses by monitoring skeletal muscle oxygenation changes during reactive hyperaemia. Despite increasing interest in the effects of sex and ageing on microvascular responses, evidence remains inconsistent. Therefore, the present study aimed to investigate the effects of sex and age on microvascular responsiveness. Twenty-seven participants (seven young men and seven young women; seven older men and six older women; aged 26±1, 26±4, 67±3 and 69±4years, respectively) completed a vascular occlusion test consisting of 5min of arterial occlusion followed by 5min reperfusion. Oxygenation changes in the vastus lateralis were monitored by near-infrared spectroscopy. The findings revealed that both women (referring to young and older women) and older participants (referring to both men and women) exhibited lower microvascular responsiveness. Notably, both women and older participants demonstrated reduced desaturation (-38% and -59%, respectively) and reperfusion rates (-24% and -40%, respectively) along with a narrower range of tissue oxygenation (-39% and -39%, respectively) and higher minimal tissue oxygenation levels (+34% and +21%, respectively). Women additionally displayed higher values in resting (+12%) and time-to-peak (+15%) tissue oxygenation levels. In conclusion, this study confirmed decreased microvascular responses in women and older individuals. These results emphasize the importance of considering sex and age when studying microvascular responses. Further research is needed to uncover the underlying mechanisms and clinical relevance of these findings, enabling the development of tailored strategies for preserving vascular health in diverse populations.

Sex-specific microvascular and hemodynamic responses to passive limb heating in young adults.

We examined sex-specific microvascular reactivity and hemodynamic responses under conditions of augmented resting blood flow induced by passive heating compared to normal blood flow. Thirty-eight adults (19 females) completed a vascular occlusion test (VOT) on two occasions preceded by rest with or without passive heating in a randomized, counterbalanced order. Skeletal muscle tissue oxygenation (StO2, %) was assessed with near-infrared spectroscopy (NIRS), and the rate of desaturation and resaturation as well as maximal StO2 (StO2max) and prolonged hypersaturation (area under the curve, StO2AUC) were quantified. Before the VOT, brachial artery blood flow (BABF), vascular conductance, and relative BABF (BABF normalized to forearm lean mass) were determined. Sex × condition ANOVAs were used. A p-value ≤.05 was considered statistically significant. Twenty minutes of heating increased BABF compared to the control (102.9 ± 28.3 vs. 36.0 ± 20.9 mL min-1; p < .01). Males demonstrated greater BABF than females (91.9 ± 34.0 vs. 47.0 ± 19.1 mL min-1; p < .01). There was no sex difference in normalized BABF. There were no significant interactions for NIRS-VOT outcomes, but heat did increase the rate of desaturation (-0.140 ± 0.02 vs. -0.119 ± 0.03% s-1; p < .01), whereas regardless of condition, males exhibited greater rates of resaturation and StO2max than females. These results suggest that blood flow is not the primary factor causing sex differences in NIRS-VOT outcomes.

Arterial desaturation rate does not influence self-selected knee extension force but alters ventilatory response to progressive hypoxia: A pilot study.

The absolute magnitude and rate of arterial desaturation each independently impair whole-body aerobic exercise. This study examined potential mechanisms underlying the rate-dependent relationship. Utilizing an exercise protocol involving unilateral, intermittent, isometric knee extensions (UIIKE), we provided sufficient reperfusion time between contractions to reduce the accumulation of intramuscular metabolic by-products that typically stimulate muscle afferents. The objective was to create a milieu conducive to accentuating any influence of arterial desaturation rate on muscular fatigue. Eight participants completed four UIIKE sessions, performing one 3 s contraction every 30s at a perceived intensity of 50% MVC for 25 min. Participants voluntarily adjusted their force generation to maintain perceptual effort at 50% MVC without feedback. Reductions in inspired oxygen fraction (FI O2 ) decreased arterial saturation from >98% to 70% with varying rates in three trials: FAST (5.3 ± 1.3 min), MED (11.8 ± 2.7 min), and SLOW (19.9 ± 3.7 min). FI O2 remained at 0.21 during the control trial. Force generation and muscle activation remained at baseline levels throughout UIIKE trials, unaffected by the magnitude or rate of desaturation. Minute ventilation increased with hypoxia (p < 0.05), and faster desaturation rates magnified this response. These findings demonstrate that arterial desaturation magnitude and rate independently affect ventilation, but do not influence fatigue development during UIIKE.

Averaging Times for Pulse Oximeter Measurements - A Review of Manuscripts Published in the Top Five Sleep Medicine Journals.

Clinical management decisions often rely on a patient's SpO2 level and desaturation rate. Limitations include that measurements depend on the averaging time (AVT) used, which is particularly relevant to sleep medicine, but has yet received little attention. Cross-sectional review of studies reporting pulse oximeter saturation (SpO2) measurements published in 5 leading sleep medicine journals. All papers published between 2017 and 2023 reporting SpO2 measurements were screened regarding the AVT used. Of 193 papers identified, 151 were included; of these, only 9 studies mentioned the AVT, 4 of these were published in one journal. The AVT ranged from zero (beat-to-beat-mode) to 10s, with 3s being used most often (33.3%), followed by 2s (22.2%). The AVT is only rarely mentioned in sleep medicine papers, despite its influence on sleep study results. Reported AVTs were heterogenous. Further research is warranted to set up guidelines for using or reporting the AVT.

Noninvasive Neurally Adjusted Ventilation versus Nasal Continuous or Intermittent Positive Airway Pressure for Preterm Infants: A Systematic Review and Meta-Analysis.

The noninvasive neurally adjusted ventilatory assist (NIV-NAVA) is a newly developed noninvasive ventilation technique with promising clinical and ventilatory outcomes for preterm infants. This systematic review and meta-analysis aimed to investigate whether NIV-NAVA has better clinical and ventilatory outcomes than nasal continuous airway pressure (NCPAP) or noninvasive positive pressure ventilation (NIPP) on premature infants. MEDLINE, Embase, and CENTRAL were searched, and randomized controlled trials (RCTs) that compared NIV-NAVA with NCPAP or NIPP for preterm infants (gestational age: <37 weeks) were included. We evaluated the following outcomes in the neonatal intensive care unit: the desaturation rate, failure of noninvasive modality requiring intubation when received as the primary mode or the need for re-intubation after extubation from mechanical ventilation in the secondary mode (weaning), length of stay, and fraction of inspired oxygen. The mean difference and risk ratio were used to represent continuous and dichotomous outcomes, respectively. We included nine RCTs involving 339 preterm infants overall. NIV-NAVA showed similar clinical and ventilatory outcomes to NCPAP or NIPP, except for the maximum diaphragmatic electrical activity. The rate of failure of the noninvasive modality was not statistically different between NIV-NAVA and NCPAP. The pooled estimates for the maximum electrical activity were significantly reduced in NIV-NAVA compared with those in NIPP. The findings suggest that NIV-NAVA may be as safe and effective as NCPAP and NIPP for preterm neonates, particularly those who may not tolerate these alternative noninvasive methods. However, further trials are recommended for greater evidence.

Use of NIRS to explore skeletal muscle oxygenation during different training sessions in professional boxing

PurposeThe physiological examination of boxing has been limited to systemic response in amateur athletes. The demands of professional boxing have been overlooked, despite the different competition format. We sought to determine the physiological demands placed on skeletal muscle in professional boxing.MethodsTen male professional boxers (age 26 ± 5 years, height 177 ± 4 cm, weight 71 ± 6 kg) were recruited for this observational study. On different days, the athletes completed 6 × 3 min rounds of pad, bag or spar-based training with 1 min recovery between each round. Prior to each session, participants put on a heart rate monitor and near-infrared spectroscopy attached to the belly of the rectus femoris muscle to record heart rate and muscle oxygenation.ResultsThere were significantly less punches thrown in sparring compared to other training modalities (p < 0.001). Skeletal muscle oxygenation across training modalities consisted of a delay, fast desaturation and steady state. Across rounds there was a significant increase in time delay for desaturation (p = 0.016), rate of fast desaturation (p < 0.001) and duration of fast desaturation (p = 0.019). There was a significant difference in sparring for the heart rate where skeletal muscle oxygenation changes occurred compared to pads or bag sessions (p < 0.001).ConclusionThe findings highlight differences in the skeletal muscle response to the different training modalities. Practitioners need to be aware of the muscular demands of each session to allow optimal adaptation across a training camp. Training needs to allow the skeletal muscle to achieve a new oxygenation steady state rapidly to promote efficient performance across rounds.

The impact of residency training level on early postoperative desaturation: A retrospective multicenter cohort study

ObjectiveWe studied the primary hypothesis that the training level of anesthesiology residents (first clinical anesthesia year, CA1 vs CA2/3 residents) is associated with early postoperative desaturation (oxygen saturation < 90%). We also analyzed the change in the rate (trajectory) of desaturation during the resident's development from CA1 to CA2/3 resident, and its effects on postoperative respiratory complications. DesignRetrospective hospital registry study. SettingTwo university-affiliated hospitals networks (MA and NY, USA). Patients140,818 adults undergoing non-cardiac surgery under general anesthesia and extubation in the operating room by residents (n = 378) between 2005 and 2021. MeasurementsMultivariate logistic and quantile regression were used in the analyses. The secondary outcome was major respiratory complication within 7 days after surgery. Main resultsIn 6.5% and 1.6% of cases, early postoperative desaturation to < 90% and 80% occurred. Compared to CA2/3 residents, CA1 residents had higher odds of experiencing early postoperative desaturation to < 90% and 80% (adjusted odds ratio [ORadj], 1.07; 95%CI 1.03–1.12; p = 0.002, and ORadj 1.10; 95%CI 1.01–1.20; p = 0.037, respectively). The change in postoperative desaturation rate during the transition from CA1 to CA2/3 status varied substantially from ORadj 0.80 (decreased risk) to 1.33 (increased risk). Major respiratory complication did not differ between experience levels (p = 0.52). However, a strong decline in improvement regarding the rate of postoperative desaturation during the transition from CA1 to CA2/3, was paralleled by an increased odds of major respiratory complication for CA2/3 residents (ORadj 1.20; 95%CI 1.02–1.42; p = 0.026, p-for-interaction = 0.056). ConclusionPatients treated by CA1 residents have an increased risk of postoperative desaturation. Some residents show an improvement and others a decline in postoperative desaturation rate. Our secondary analysis suggests that there should be more focus on those residents who had a declining performance in postoperative desaturation despite becoming more experienced.

Postoperative pulmonary complications after sugammadex reversal of neuromuscular blockade: a systematic review and meta-analysis with trial sequential analysis

BackgroundSugammadex has been reported to lower the incidence of postoperative residual neuromuscular blockade. Despite the advantages, until recently the effects of sugammadex on postoperative pulmonary complications (PPCs) were controversial. We conducted a systematic review and meta-analysis to determine whether reversal with sugammadex was associated with a lower risk of PPCs compared with neostigmine.MethodsPubMed, Embase, and Cochrane Central Register of Controlled Trials were searched from inception to May 2022. Randomized controlled trials (RCTs) and observational studies comparing PPCs in patients receiving sugammadex or neostigmine as reversal agent at the end of surgery were included. The primary outcomes focused on PPCs including desaturation, pneumonia, atelectasis, noninvasive ventilation (NIV) and reintubation. Trial sequential analysis was performed on the primary outcomes to confirm whether firm evidence was reached.ResultsMeta-analysis of included studies showed that the rate of desaturation (43.2% vs 45.0%, RR = 0.82; 95% CI 0.63 to 1.05; p = 0.11) were comparable between the two groups. When looking at other primary outcomes, significantly lower risk of pneumonia (1.37% vs 2.45%, RR = 0.65; 95% CI 0.49 to 0.85; p = 0.002), atelectasis (24.6% vs 30.4%, RR = 0.64; 95% CI 0.42 to 0.98; p = 0.04), NIV (1.37% vs 2.33%, RR = 0.65; 95% CI 0.43 to 0.98; p = 0.04) and reintubation (0.99% vs 1.65%, RR = 0.62; 95% CI 0.43 to 0.91; p = 0.01) in the sugammadex group were detected compared with the neostigmine group.ConclusionsWe concluded that sugammadex is more effective at reducing the incidence of PPCs including pneumonia, atelectasis, NIV and reintubation compared with neostigmine. Further evidence, preferably from RCTs, is required to confirm these findings.

Underwater pulse oximetry reveals increased rate of arterial oxygen desaturation across repeated freedives to 11 metres of freshwater.

Recreational freedivers typically perform repeated dives to moderate depths with short recovery intervals. According to freediving standards, these recovery intervals should be twice the dive duration; however, this has yet to be supported by scientific evidence. Six recreational freedivers performed three freedives to 11 metres of freshwater (mfw), separated by 2 min 30 s recovery intervals, while an underwater pulse oximeter measured peripheral oxygen saturation (SpO2) and heart rate (HR). Median dive durations were 54.0 s, 103.0 s and 75.5 s (all dives median 81.5 s). Median baseline HR was 76.0 beats per minute (bpm), which decreased during dives to 48.0 bpm in dive one, 40.5 bpm in dive two and 48.5 bpm in dive three (all P < 0.05 from baseline). Median pre-dive baseline SpO2 was 99.5%. SpO2 remained similar to baseline for the first half of the dives, after which the rate of desaturation increased during the second half of the dives with each subsequent dive. Lowest median SpO2 after dive one was 97.0%, after dive two 83.5% (P < 0.05 from baseline) and after dive three 82.5% (P < 0.01 from baseline). SpO2 had returned to baseline within 20 s after all dives. We speculate that the enhanced rate of arterial oxygen desaturation across the serial dives may be attributed to a remaining 'oxygen debt', leading to progressively increased oxygen extraction by desaturated muscles. Despite being twice the dive duration, the recovery period may be too short to allow full recovery and to sustain prolonged serial diving, thus does not guarantee safe diving.

Role of Stearoyl-CoA Desaturase 1 in Cardiovascular Physiology.

Stearoyl-CoA desaturase is a rate-limiting enzyme in the synthesis of monounsaturated fatty acids. Monounsaturated fatty acids limit the toxicity of exogenous saturated fats. Studies have shown that stearoyl-CoA desaturase 1 is involved in the remodeling of cardiac metabolism. The loss of stearoyl-CoA desaturase 1 reduces fatty acid oxidation and increases glucose oxidation in the heart. Such a change is protective under conditions of a high-fat diet, which reduces reactive oxygen species-generating β-oxidation. In contrast, stearoyl-CoA desaturase 1 deficiency predisposes individuals to atherosclerosis under conditions of hyperlipidemia but protects against apnea-induced atherosclerosis. Stearoyl-CoA desaturase 1 deficiency also impairs angiogenesis after myocardial infarction. Clinical data show a positive correlation between blood stearoyl-CoA Δ-9 desaturation rates and cardiovascular disease and mortality. Moreover, stearoyl-CoA desaturase inhibition is considered an attractive intervention in some obesity-associated pathologies, and the importance of stearoyl-CoA desaturase in the cardiovascular system might be a limitation for developing such therapy. This review discusses the role of stearoyl-CoA desaturase 1 in the regulation of cardiovascular homeostasis and the development of heart disease and presents markers of systemic stearoyl-CoA desaturase activity and their predictive potential in the diagnosis of cardiovascular disorders.

Risk factors for impaired respiratory function post COVID-19: A prospective cohort study of nonhospitalized and hospitalized patients.

Severe COVID-19 increases the risk for long-term respiratory impairment, but data after mild COVID-19 are scarce. Our aims were to determine risk factors for reduced respiratory function 3-6 months after COVID-19 infection and to investigate if reduced respiratory function would relate to impairment of exercise performance and breathlessness. Patients with COVID-19 were enrolled at the University Hospitals of Umeå and Örebro, and Karlstad Central Hospital, Sweden. Disease severity was defined as mild (nonhospitalized), moderate (hospitalized with or without oxygen treatment), and severe (intensive care). Spirometry, including diffusion capacity (DLCO ), was performed 3-6 months after hospital discharge or study enrollment (for nonhospitalized patients). Breathlessness (defined as ≥1 according to the modified Medical Research Council scale) and functional exercise capacity (1-min sit-to-stand test; 1-MSTST) were assessed. Between April 2020 and May 2021, 337 patients were enrolled in the study. Forced vital capacity and DLCO were significantly lower in patients with severe COVID-19. Among hospitalized patients, 20% had reduced DLCO , versus 4% in nonhospitalized. Breathlessness was found in 40.6% of the participants and was associated with impaired DLCO . A pathological desaturation or heart rate response was observed in 17% of participants during the 1-MSTST. However, this response was not associated with reduced DLCO . Reduced DLCO was the major respiratory impairment 3-6 months following COVID-19, with hospitalization as the most important risk factor. The lack of association between impaired DLCO and pathological physiological responses to exertion suggests that these physiological responses are not primarily related to decreased lung function.

Muscle oxygenation of the paretic and nonparetic legs during and after exercise in chronic stroke: Implications for mobility.

Oxygen delivery and demand are reduced in the paretic leg of individuals after stroke. However, it is unknown how muscle oxygenation, the balance between delivery and utilization of oxygen at the muscle, is altered post-stroke during aerobic exercise and how it relates to mobility. To monitor muscle oxygenation changes between the paretic and nonparetic legs of individuals after stroke during treadmill exercise and the 6-minute walk test and analyze the association with mobility. Cross-sectional study. Cardiac rehabilitation program. Eleven male participants were enrolled in the study. Ten men (30.8 ± 4.1months post-stroke; age 63.9 ± 13.9 years) with hemiparetic gait pattern finished the study. Not applicable. Muscle oxygenation was measured with near-infrared spectroscopy placed on the vastus lateralis of each leg during treadmill exercise at the first ventilatory threshold and during a 6-minute walk test. The desaturation slope during treadmill exercise was significantly steeper (p=.047) in the paretic (-0.7 ± 0.6%/s) compared to the nonparetic leg (-0.3 ± 0.2%/s). There was no other significant difference between legs. The 6-minute walk test distance was not correlated with 6-minute walk test muscle oxygenation in either leg (paretic: r=0.20, p=0.590; nonparetic: r=0.42, p=.232). At the onset of treadmill exercise, the paretic leg was unable to effectively match the oxygen demand and extraction of the nonparetic leg, suggesting the need for an immediate cardiovascular warmup prior to initiating moderate intensity exercise in this population. Because the exercise desaturation rate is thought to indicate increased anaerobic metabolism and lactate production, efforts to delay rapid desaturation could improve the sustainability of activities of daily living and exercise.